Golf is enjoyed by a wide variety of players—players of different genders and dramatically different ages and/or skill levels. Golfers at all skill levels seek to improve their performance, lower their golf scores, and reach that next performance “level.” One way to improve performance is to use more technologically advanced equipment. A further way to improve performance is to select equipment that matches an individual golfer's style.
Golf clubs have been the subject of much technological research and advancement in recent years. Certain technological advancements have been made in an effort to better match the various elements and/or characteristics of the golf club and characteristics of a golf ball to a particular user's swing characteristics (e.g., club fitting technology, ball launch angle measurement technology, ball spin rates, etc.). There now exists a vast array of golf club component parts available to the golfer. For example, individual club head models may include variations in the loft angle, lie angle, offset features, weighting characteristics, etc. These various club heads may be combined with a variety of shafts having, for example, any of various stiffnesses, flex points, kick points or other flexion characteristics. Between the available variations in shafts and club heads, there are literally hundreds of different club head/shaft combinations available to the golfer.
Club fitters and golf professionals can assist in fitting golfers with a golf club head/shaft combination that suits their swing characteristics and needs. Not only should the individual golf head and shaft be selected based on the specific golfer's swing characteristics, but the angle at which the shaft is fitted to the head, i.e. the lie angle, should also be matched to the individual golfer's physical characteristics.
Lie is the angle between the center line of the hosel and the sole of the club head when the sole is touching the ground at the center of the face scoring area. If the center of the face scoring area of the club head is on the ground when a golfer stands at address then the lie of the club is generally considered perfect—this is termed a “standard” lie. If the toe of the club head points in the air and the heel of the club head is on the ground, then the golfer's lie is too “upright” and should be made flatter. In contrast, if the heel of the club head is in the air and the toe is on the ground, then the golfer's lie is too “flat” and should be made more upright. Shorter players generally use a flatter lie angle; taller players generally use a more upright lie angle.
The lie of the club can have a significant impact on ball flight. If the lie is too flat for a particular golfer, the toe of the club head may impact the ground first and the ball flight may tend to the right. If the lie of the club is too upright for the golfer, the ball flight may tend to the left.
Conventionally, shafts are mounted to golf club heads using hosels. In some instances, custom-fitting of golf clubs to an individual golfer has involved bending the hosel to provide the correct lie angle for that golfer/club combination. This is typically undesirable. First, the hosel, which is a structural connection between the shaft and the club head, may optimally have material properties that are not amenable to bending. Further, bending may result in deformation of the hosel and some attendant loss of strength and/or stiffness.
In other instances, particularly with drivers, the shaft may be inserted into a bore within the club head. By providing club heads with various bore angles, the lie angle of the club may also be varied. As each club head can only accommodate a single bore angle, and correspondingly can only accommodate a single lie angle, this system does not make efficient use of the golf club components that must be stocked by golf club customizers.
The disadvantages associated with these conventional options serve to limit the choices available to a golfer during a custom-fitting session and/or to reduce the technical performance of the golf club.